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目的利用ITS2序列对紫苏子及其混伪品进行快速、有效地鉴定,以确保药品质量和临床用药安全。方法以紫苏子及其常见混伪品为研究对象,从GenBank中下载紫苏子及其混伪品的ITS2序列,利用软件MEGA6.06对ITS2序列的长度、GC含量等分析比对,基于K2P模型计算遗传距离,应用Schultz等建立的ITS2数据库及其网站预测其ITS2二级结构,通过中药材DNA条形码鉴定系统和构建邻接树(NJ树)法对紫苏子及其混伪品进行鉴定。结果紫苏子及其混伪品ITS2序列间存在明显差异,种内遗传距离远远小于种间遗传距离。比较ITS2二级结构发现,紫苏子及其混伪品在4个螺旋区的茎环数目、大小、位置以及螺旋发出时的角度均有明显差异,很容易区分紫苏子及其混伪品。结论 DNA条形码的ITS2序列为紫苏子及其混伪品的快速、准确鉴定提供了新的分子鉴定方法,利于确保药品质量和临床用药安全。
OBJECTIVE: To rapidly and effectively identify Perilla frutescens and its adulterants using ITS2 sequence to ensure the quality of medicines and the safety of clinical medication. Methods The Perilla frutescens seeds and its common mimicry were used as research objects. The ITS2 sequences of Perilla frutescens and its adulterants were downloaded from GenBank. The length and GC content of ITS2 sequences were analyzed by software MEGA6.06. K2P model was used to calculate the genetic distance. The ITS2 database established by Schultz et al. And its website were used to predict the ITS2 secondary structure. Perilla seed and its adulterants were identified by DNA barcode identification system of Chinese herbal medicines and constructing NJ tree . Results There were significant differences in ITS2 sequences between Perilla frutescens and its adulterants. The intraspecies genetic distance was much less than the interspecific genetic distance. Comparing ITS2 secondary structure found that perilla and its adulterants in the four spiral zone stem ring number, size, location and the angle of the spiral when there are significant differences, it is easy to distinguish Perilla and its adulterants . Conclusion ITS2 sequence of DNA barcode provides a new molecular identification method for the rapid and accurate identification of Perilla frutescens and its adulterants, which helps to ensure the quality of medicines and the safety of clinical medication.